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Some help for a first time user: adherence and fan speed

Posted: Wed Sep 28, 2016 3:55 am
by morganfree
Hello to everybody!
I'm new to the group and with 3D printers! I received my MG M2 yesterday! Only today I had the chance to print something (calibration models from the tips and getting start topics).
So, It took me more than a day after I had the CORAGE of printing for the first time!!!

I read all of the threads (I can tell) about getting started, configuration, setups, filaments, adherence, etc.etc. I can tell I went quite good (at least I'm happy) with Z-Calibrations, Bed Level and also with extrusion calibration: the three models printed were fine (the grid, the cube with infills and the cube without them).

BUT!

Almost everything I printed had little or almost nothing of adherence to the platform! The nozzle is almost "dragging" the first layer...

I'm using hairspray (I did the way I read somewhere here: applying layers of spray, letting them dry between one application and another, 6 layers); I'm printing PLA at T° Extruder/220 C°& table/70 C°.

I tried correcting the G-Code Z-Global height (in S3D), lowering the speed for the first layer (up to 30%) and lowering the fan speed after the first layer. But the problems are still.

I finally tried putting a layer of stick glue to the table and worked fine for a while. The first layer remained glued at the beginning, but after a few layer after, appeared the other problem: the part unglued in some zones and finally deforms.

Some questions:
1) Should I use heated platform when I use hair spray with PLA? (maybe that's my first problem, I'm thinking the spray dried with the T°...)
2) The stick glue should be used with cool or hot table? (same than with hair spray). Should I wash the table after every print if I use glue?
3) About the "Deformation" of the part: Should I let the fan speed go maximum after the first layer (that is happening and I read that that situation might cause some problems...)

These are specific questions I have... but of course I receive any advice from you!

Thank you very much!

Re: Some help for a first time user: adherence and fan speed

Posted: Fri Sep 30, 2016 9:51 pm
by insta
You're printing too hot on the bed (use 55-60C), but are you sure your first layer height is correct? Check the stickies, there's lots of information around for getting that right. It's absolutely mandatory.

Re: Some help for a first time user: adherence and fan speed

Posted: Fri Sep 30, 2016 11:35 pm
by Jules
If you have a Rev.E model of the machine (just bought it new), a lot of the Z-Calibration information doesn't apply to your machine. The new models use the Quick Start App to set the Starting Height. Adjustments to the Z-Offset in S3D don't accomplish anything for the new machines.

Beginner's Guide for the Rev.E machines: viewtopic.php?f=3&t=3542

If you used that, your Starting Height might be a little bit too low. (too much gap)

If you can upload a photo or two of the first layer (just cancel the print after the first layer is about halfway done and take a fairly tight photo) we can probably tell if you need to adjust that gap a little by looking at it.

Re: Some help for a first time user: adherence and fan speed

Posted: Sat Oct 01, 2016 2:47 am
by morganfree
Thank you both for your answers!
Since my post took a little bit to be actually posted, I continue looking for solutions to my problems, and at this moment I can say that I'm printing with less problems (evethough every day appears a new situtation... haha).

- The bed is now at 60C, as Insta suggest.
- About the firts layer height I had many problems: The Z-Stop configuration was always messing due to low fixation of the Z sensor... therefore after a few Z-0s, I had troubles. It took me a while until I notice that and correct it.
- Another problem was the hairspray itself: I was using too little. Eventhough I thought I had some good layers of hairspray, I needed more. I don't have that issue any longer, neither.

Jules, I guess I don't have a REV E machine (how can I know?) since I bought a used machine and I don't know when the machine was originally bought. The only things I know are that the extruder is a V3b, the Z engine is not black (grey with black stripe) and the "spider" is the one with three bolts. What REV is that printer?

About the deformations, well, I still have some little deformations but only after the part is unglued from the bed. I definitelly decrease the extruder temp to 205/200 C for the PLA and I'm getting better results. Maybe I still some more little adjustments... Any suggestion?

Another thing I tried was the tape that comes with the machine. I could apply it very well to the glass (no bubbles no stripes) but it didn't fixed at all the PLA once extruded. Did I missed something? Or is it just not suitable for PLA? Is is something related to cleaning or T° of the bed?

Thank you for your support, again.

Best regards,